When adding a new gabled roof addition to your home, you will need to find a way of joining the two roofs together. Called "tying in," this helps to weatherproof and strengthen the joint.
Step 1 - Planning
As every roof is unique, you will need to plan for each type of roof addition project that you undertake. Give special consideration to the two roofs and how they will work with one another. Draw a complete plan of how the roofs will fit together before even starting the project. Also, take this plan to a friendly architect to ensure that all of the building codes are met and that the roof addition will be completely safe.
Step 2 - Preparation
Once you know what to do you will then need to prepare the roof by removing the tiles from the old roof where the new roof will join. The new roof will need to be cut to the right angle so that it fits snugly against the roof. This is important to minimize the chance of any water being able to penetrate the gap.
Step 3 - Connecting the New Roof
The new roof now needs to be connected by nailing through the board into the joists. This is an important job and needs to be done carefully. Spend time doing this to ensure that the nails all go through the joists and securely hold the new roof in place.
Step 4 - Finishing the Roof
Now the new roof can be finished by adding the rafters and covering the whole thing in plywood. After this, the shingles can be fixed onto the plywood to create the finished roof. The roof simply needs to be finished as normal but the shingles will need to be cut at an angle so that they fit snugly up against the original roof.
Step 5 - Sealing the Roof
Once the roof is finished you will then need to seal the joint between the new and the old roof. the joint should be sealed with plenty of roofing compound and then the old tiles need to be replaced. You must spend time carefully sealing the roof so that the joints aren't a weakness.
Step 6 - Flashing
Flashing can now be applied to the gap to ensure that it is completely weatherproof and watertight. Once you have finished you will need to keep a close eye on the joint between the roofs to ensure that the joint doesn't start to leak or cause any problems.